Note: City positioned on 7 hills over the swampy Tiber river area; one of the oldest continuously occupied sites in Europe. Archaeological evidence attests to human occupation of the area from ca. 14,000 years ago, but the dense layer of later debris obscures Palaeolithic and Neolithic sites. Was an Etruscan city by 8th cen. BCE, their kings expelled and republic established by 500 BCE; soon ruled vast area and was center of Empire from 31 BCE; declined when capital moved to Constantinople in 330 CE; revived under popes.